In general, Hough transform is widely used to extract a line from an image. The Hough transform is a method of searching for an extreme point expressing a line segment by transforming a space for an image into a Hough space and of searching for a line from the image using a reverse Hough transform. Researches are being conducted to obtain methods of searching an extreme point in the Hough space.
In an image, the line segment is one of information that may be useful in various fields of image processing. Hence, researches are being actively carried out to search for a line segment from an image. However, the extraction of the line segment from an image cannot be achieved just by searching for features from the image, and no effective methods of extracting a line segment from an image has yet been proposed. Due to this, as one of methods of extracting a line segment from an image, there is the above-mentioned method using a Hough transform may be applied to search for a line segment from an image. However, in a case of searching for a line segment using the Hough transform, more line segments may be searched than are needed to understand an image. In addition, a user must participate to search the for a line segment. Accordingly, it is difficult to automatically search for the line segment from an image.